i have a electric mower and would never trade it in for a gas model. as stated above, electric is cleaner, quieter, easier to start, you can turn it over to check underneath without worrying about oil/gas/etc spilling, no storing of gasoline next to home, no gas smell, no tune ups, no spark plugs/filters, etc.
all around easier to use. if you have a smaller yard without lots of trees, bushes, rocks, etc. then you might even think about a electric mower with a cord. even lighter and easier to use. cord is a bit of a pain, but you learn to get around with no real trouble.
and, if you use a cord, you can also use an electric snow blower in the winter.
good luck to you.